# refactor.py
"""
Change typing import style for python files
    'import typing' -> 'from typing import Any,cast,...'
    'typing.Any' -> 'Any'
    'typing.cast' -> 'cast'
    'typing.ContextManager' -> 'contextlib.AbstractContextManager'
"""

import re
from pathlib import Path

for d in (Path().resolve().name, "tests"):
    for p in Path(d).rglob("*.py"):
        s = p.read_text()
        t = "import typing"
        if t not in s:
            continue
        pattern = re.compile(r"(\W?)typing\.(\w+)(\W)")
        ws = set([i[1] for i in pattern.findall(s)])
        imports = "from typing import "
        for cm in ("ContextManager", "AsyncContextManager"):
            if cm not in ws:
                continue
            # typing.ContextManager -> contextlib.AbstractContextManager
            # typing.AsyncContextManager -> contextlib.AbstractAsyncContextManager
            ws.remove(cm)
            imports = f"from contextlib import Abstract{cm}\n" + imports
            s = re.sub(rf"(\W?)typing\.({cm})(\W)", r"\1Abstract\2\3", s)
        s = pattern.sub(r"\1\2\3", s)
        imports += ", ".join(sorted(ws))
        s = s.replace(t, imports)
        p.write_text(s)
        print(p, "updated.")